NASA Admits Mars Rover Permanently Stuck but Not Dead

After months of trying to extricate the Mars Exploration Rover Spirit from its Martian sand trap, NASA says its efforts have failed and reclassified Spirit as a stationary science platform. Spirit's first assignment: survive the harsh Martian winter.

Despite the ongoing efforts of NASA engineers to free the stuck Mars
Exploration Rover Spirit mired in a Martian sand trap, the space agency
admitted Jan. 26 Spirit will no longer be a fully
mobile robot. The space agency declared Spirit is now officially a
stationary science platform with the initial assignment of surviving
the Martian winter.
NASA hopes to slightly reposition Spirit in its new permanent home in
the loose soil of a site dubbed Troy. At its current angle, Spirit
probably would not have enough
power to keep communicating with Earth through the Martian winter. Even
a few degrees of improvement in tilt might make enough difference to
enable communication every few days.

It
is mid-autumn on Mars and winter begins in May. Solar energy is declining and expected to become
insufficient to power further driving by mid-February. The rover team
plans to use those remaining potential drives for improving the rover's
tilt. Spirit currently tilts slightly toward the south. The winter sun
stays in the northern sky, so decreasing the southward tilt would boost
the amount of sunshine on the rover's solar panels.

"We need to lift the rear of the rover, or the left side of
the rover, or both," said Ashley Stroupe, a rover driver at JPL.
"Lifting the rear wheels out of their ruts by driving backward and
slightly uphill will help. If necessary, we can try to lower the front
right of the rover by attempting to drop the right-front wheel into a
rut or dig it into a hole."

"Getting through the winter will all come down to temperature and how
cold the rover electronics will get," said John Callas, project manager
at JPL for Spirit and its twin rover, Opportunity. "Every bit of energy
produced by Spirit's solar arrays will go into keeping the rover's
critical electronics warm, either by having the electronics on or by
turning on essential heaters."

NASA said that even in a stationary state, Spirit continues scientific research.

"There's a class of science we can do only with a stationary
vehicle that we had put off during the years of driving," said Steve
Squyres, a researcher at Cornell University and principal investigator
for Spirit and Opportunity. "Degraded mobility does not mean the
mission ends abruptly. Instead, it lets us transition to stationary
science."

Ten months ago, as Spirit was driving south beside the western
edge of a low plateau called Home Plate, its wheels broke through a
crusty surface and churned into soft sand hidden underneath.

After Spirit became embedded, the rover team crafted plans for trying
to get the six-wheeled vehicle free using its five functioning wheels -
the sixth wheel quit working in 2006, limiting Spirit's mobility. The
planning included experiments with a test rover plus analysis, modeling
and reviews. In November, another wheel quit working, making a
difficult situation even worse.

"Spirit is not dead; it has just entered another phase of its
long life," said Doug McCuistion, director of the Mars Exploration
Program at NASA Headquarters in Washington. "We told the world last
year that attempts to set the beloved robot free may not be successful.
It looks like Spirit's current location on Mars will be its final
resting place."